As it happens, nobody has brought on any complaints, so I am releasing this set of converters.
Please note: I provide no warranty on this software, but I will be happy to provide support in this thread.
Converters for Invisionfree, ActiveBoards, MSN Groups and several other forums are provided. Please read the Instructions.txt file in the corresponding folder. I've tried my best to make these understandable, but any comments or suggestions on any part of the process are welcome.
The phpBB2 converter produces SQL which should be compatible with phpBB 2.0.22
The phpBB3 converter produces SQL which should be compatible with phpBB 3.0.0
The converters are NOT written in PHP, they are written in Python. This means that for Windows users (Linux and Mac OS X should come with Python interpreters) you will need a current distribution of the Python programming framework, available at http://python.org
(the Windows Installer link on the left is the most direct way to get it).
Note that this converter has been re-uploaded several times. Thus, the download count may not be accurate. As of time of writing, it has been downloaded about 576 times.
EDIT: I should probably also add that the ActiveBoards converter is SMF only, since no request has ever been made for a phpBB version; if you need to convert, go through SMF 1.1 and then convert to phpBB.
EDIT 2: Yuku converter removed by request from Yuku.
EDIT 3: Added board conversion feature to Proboards converter, fixed a bunch of minor bugs.
EDIT 4: Fixed moderators bug, fixed missing pages bug in Proboards converter.
EDIT 5: Added script to create bot/crawler accounts, fixed members bug (anonymous had the wrong ID!)
EDIT 6: Fixed members conversion in Invisionfree
EDIT 7: Fixed Invisionfree email links and single-quote handling (thanks pjf123 for reporting it!)
EDIT 8: Updated instructions
EDIT 9: Invisionfree fixes: fix for usernames with strange characters (< and >), fix for missing group entries. Version bump to 0.1.3.
EDIT 10: Several minor fixes for the Proboards -> phpBB3 converter, including correct code, quote and list tags, corrected font sizes, basic bbcode_bitfield handling (it should soon be possible to leave out the resync_bbcode.php step), fix for subforum topics, minor fix for internal profile links and correct date, time and user stamps on topics (thanks Kymmy for pointing this out)
EDIT 11: Added one more missing field (thanks again, Kymmy!) to Proboards, and fixed a minor username bug in the Invisionfree converter
EDIT 12: Put the _right_ version of pm_passwords in the archive...
EDIT 13: Minor fixes to make it work with the new Proboards.
EDIT 14: Improved compatibility with Proboards v4.5. Fixed split_sql to properly split phpBB3 SQL files (thanks to gonefishin for reporting this one).
EDIT 15: Oops, fixed major bug in Proboards guest post conversion -- thanks to anyways for reporting it.
EDIT 16: Minor updates to all converters to bring them up-to-date with the latest forum code. Removed PB converter (by request) and added several converters.
EDIT 17: Updates to Forumotion to compensate for new code, user_group bug off-by-one fix for nearly all phpBB2 converters, updated SuddenLaunch to correctly deal with extra pages of topics, better error handling in SuddenLaunch PM module and better error handling from common.py (affects all converters) -- all errors are now caught and retried, and major errors produce a critical_error.log file which can be used to determine the cause. Also added fora.pl -> phpBB2 converter.
The package now contains ActiveBoards, fora.pl, Forumotion, Invisionfree, iPBfree, SuddenLaunch and Zetaboards converters.
EDIT 18: Update to Forumotion to compensate for new code, iPBfree member conversion update
EDIT 19: Serious update to ZetaBoards converter, minor updates to Forumotion converter, added MSN Groups
EDIT 20: More updates to ZetaBoards (fixed serious bug in post conversion and a few minor things).